Garmin Fishfinder 160 Blue Owner's Manual

Also see for Fishfinder 160 Blue: Specifications Owner's manual

30On the WaterOn the Water112233Understanding SonarIf you are unfamiliar with sonar, or need help determining what isdisplayed on the chart, then this section may be for you. This sectionis intended to help the novice user gain some understanding of how theFishfinder 160 Blue operates and how it can help improve their fishingproductivity.To understand what the unit is displaying, it is important to have ageneral knowledge of how the unit works and how it determines what todisplay. Briefly described, the unit operates by transmitting sound wavestoward the bottom of a lake, stream or seabed in a cone–shaped pattern.When a transmitted sound wave strikes an underwater object such as thebottom, a piece of structure, or a fish, sound is reflected back to thetransducer. The transducer collects the reflected sound waves and sends thedata to the unit to be processed and displayed on the chart. Underwaterdata is displayed on the chart in the order that the reflected sound wavesare received. The diagram in the sidebar demonstrates this, showing anunderwater scene as it would be displayed on the chart. Generally speaking,if the only thing between the transducer and a flat bottom is water, thefirst strong return will come from the bottom directly below the transducer,this return will set the bottom level. Weaker secondary returns providethe detailed data. Stronger returns will display in darker colors, with blackbeing the strongest return. In Examples 1 and 2 (page 32), you can seethat the branches and the fish were the strongest secondary returns and areindicated in black on the display.That is a brief description of how your Fishfinder operates. Let’s take alook at how this data can help you to improve your fishing.Unit Operation and the ChartThis fish is currently in a Dead Zone and is not detectedby the sonar. The fish is in the coverage area of thetransducer, but remember the first strong return sets thebottom level. The fish will never be detected since thebottom level will never be set below the fish. The fish onthe right side of the display (shown in light grey) will bedetected and displayed when the transducer cone passesover the fish.www.reelschematic.comwww.reelschematic.com